Communication devices have evolved to include numerous types of communication capabilities and functionality. For example, handheld devices exist that operate as cellular phones, messaging terminals, Internet devices, while including personal information management (PIM) software and photo-management applications. Additionally, Internet Protocol services exist that can transform Internet-enabled machines into telephony devices. Even stand-alone telephones that connect to traditional Public Switched Telephone Networks (PSTN) now carry software to assist the user in making and managing phone calls.
Mobile phone networks have traditionally been limited to voice communications, but new technologies such as GSM (Global System for Mobile Communications) have enabled mobile phone networks to also include data communications. For example, SMS (Short Message Service) messaging provides a software-independent protocol to send short text messages composed of either: 160-7 bit characters; 70-16 bit characters; or 140 octets of binary data. Individual SMS messages thus require a relatively small network bandwidth and devices can receive messages, even when connected to a voice call. The number of SMS messages a user receives has continually increased because many new types of network devices have joined mobile phone networks. These devices include, for example, PDAs, hybrid PDA/mobile phone devices, and other text messaging devices using GSM networks. Additionally, PSTN devices also exist that support messaging applications such as SMS.